Evaluation On The Soil Profile Quality Of Luvisols In Henan Province Based On Soil Taxonomy

The soil quality and regulation to the sustainable and healthy development become the urgently global problem,such as the population growth,farmland decreases and energy crisis.The soil quality research is concentrated in the surface soil quality evaluation,while the soil as a natural entity,profile feature on soil functions has great direct impact on soil productivity.The soil taxonomy on the soil quality assessment has important guiding significance in terms of the soil profile feature and the quantitative soil taxonomy based on diagnostic horison and diagnostic characteristic.The quality of the luvisols profile in the soil taxonomy has scientific and practical significance in improving the agrology,preventing soil degradation,ensuring soil health and food security in Henan province.The 35 soil points distributed in Zhengzhou,Sanmenxia,Luoyang,Nanyang,Xinyang and other cities of Henan province were tested and analyzed.They were classified into 2 suborders,5 groups,13 subgroups,20 families and 35 series according to the the soil taxonomy index.The concept of the soil profile quality was defined according to the different adaptation of soil stratums and soil properties to the crop root growth.First,the LQI(layer quality index)was established on the soil properties of each soil series.Then,the SPQI(soil profile quality index)was established on the LQI to evalute the soil profile production performance quantificationally.The results show that the SPQI of luvisols were ranged from 36 to 60,and it presented a gradient distribution at all levels taxon under the same senior taxon.From a general view,the SPQI of ustic luvisols was slightly higher than udic luvisols;in group,the SPQI of most hapli-ustic luvisols and hapli-udic luvisols was higher;in subgroup,the SPQI of typical hap ustic luvisols was higher,the SPQI of calcic hapli-udic luvisols was the lowest.The main factors that affected SPQI were the soil texture,soil organic matter and the position and thickness of argic horizon.The ideal profile was simulated based on different textures in order to explore the influence of the position and thickness of argic horizon on SPQI.The results show that the deeper argic horizon location,the higher SPQI while the overal profile texture of the soil change from more loam to sticky soil,and the deeper argic horizon location,the lower SPQI while the overal profile texture of the soil change from sandy loam to mealy loamy under the premise of other indicators unchanged.In sum,the position and thickness of argic horizon would affect the soil profile quality of uvisols with other factors.At last,it has good fitting by the comparative analysis of the research results and the natural quality of agricultural land classification results,and the fitting degree is0.706,which shows that the results are reliable.